First, there was BillAndTed?.
Next, there was WayneAndGarth?.
Now, there's JayAndSilentBob.
A running joke that started as two minor characters in Clerks, a couple of lowlifes who hung around the front of a convenience store selling drugs. Jay was played by Jason Mewes, a friend of Clerks' director Kevin Smith, who in turn played Silent Bob. Silent Bob, as his name implies, is mute for most of the movie, until the very end where he speaks a single line which seems to encapsulate infinite wisdom.
These two characters then appeared in Smith's next movie, Mallrats. Not wiki-named because it's not a movie worth much note. Jay and Silent Bob are now selling marijuana at the local mall, at which much of this movie is set. They have a much more vital role in the movie's plot. Silent Bob, again, remains silent through most of the movie, until the very end when he speaks a single line which is pretty much a lame StarWars quote.
When Smith made another movie, Chasing Amy, he threw in these characters again. This time, Silent Bob is a total chatterbox, but at least he has his wisdom back.
it's late... someone else fill in the rest of their history. The comic books, the animated series, and even a movie not produced by Kevin Smith.
They were part of the ensemble cast in Dogma, which was pretty good. And Silent Bob's one spoken line ("No ticket!", a reference to the last Indiana Jones movie) is hilarious; at least, I found it so.
Jay And Silent Bob Strike Back was a cult movie for fans of Kevin Smith. It's filled with references to Smith's other movies, and also to StarWars.
Those who study MemeTheory? could do well to write papers about this duo.
Here's the question: Are they so popular for any other reason that they've become familiar to us through so many eclectic works, even though they are by no means independent?
See also: CatchPhraseDuos?